Abstract

The combination of Z‐contrast scanning transmission electron microscopy,transmission electron microscopy, and secondary ion mass spectroscopy allows the most accurate determination, to date, of the As doping profile across the polycrystalline Si/Si interface of an npnpolycrystalline Si emitter bipolar transistor. We measure a peak in the As doping profile which is coincident with the polycrystalline Si/Si crystallographic interface and is approximately 40 Å full width at half‐maximum. There is a uniform As dopant level in the polycrystalline Si emitter of 2×1020 cm−3 and an estimated maximum As concentration of 5×1020 cm−3 in the peak at the interface.